A Buddy for Sunfish

Here's your nightly math! Just 5 quick minutes of number fun for kids and parents at home. Read a cool fun fact, followed by math riddles at different levels so everyone can jump in. Your kids will love you for it.

A Buddy for Sunfish

Did you know there’s a fish called the sunfish? And if that’s its name, what’s the opposite of a sunfish? A moonfish! These fish are pretty different from each other, other than the fact that they’re both fish. The sunfish is a huge, not-so-cute creature that can weigh 2,000 pounds or more and grow to as long as 12 feet. It likes to swim near the surface (top) of the water to warm up in the sun; sometimes people mistake it for a shark when its fin sticks out of the water. But the sunfish is nice to people and just eats jellyfish. The moonfish is another story: it’s warm-blooded like us humans, while most fish are cold-blooded. It’s also smaller than the sunfish, although the moonfish is still as big as a truck tire and weighs around 600 pounds. Also, while the sunfish is plain whitish-gray, the moonfish is orangey-pink with brightly colored fins. But whether they’re good-looking or not, they’re both too big to keep as a pet.

Wee ones: If you have 2 pet sunfish and 2 pet moonfish, how many fish do you have?

Little kids: If you have 9 pet fish and 6 of those are sunfish, how many could be moonfish? Bonus:If a baby moonfish eats 3 jellyfish a day and its mom eats 10 times as many, how many does the mom eat?

Big kids: Sunfish are about 12 feet long, and moonfish are about half as long. How long are moonfish? Bonus: Which is heavier, your 4,200-pound car, or a pair of 2,200-pound sunfish?

About the Author

Laura Bilodeau Overdeck is founder and president of Bedtime Math Foundation. Her goal is to make math as playful for kids as it was for her when she was a child. Her mom had Laura baking while still in diapers, and her dad had her using power tools at a very unsafe age, measuring lengths, widths and angles in the process. Armed with this early love of numbers, Laura went on to get a BA in astrophysics from Princeton University, and an MBA from the Wharton School of Business; she continues to star-gaze today. Laura’s other interests include her three lively children, chocolate, extreme vehicles, and Lego Mindstorms.